There have been explosive increases in our understanding of the molecular basis of adipogenesis and obesity. In particular, the transcriptional basis of fat cell formation is now known to involve an interplay between PPARgamma and the C/EBP family. Adding further interest is the fact that PPARgamma is also the functioning receptor for the thiazolidinedione insulin-sensitizing drugs. After adipose cells differentiate, they influence whole body energy homeostasis through the production and secretion of leptin. This circulating molecule affects both food intake and energy dissipation through mechanisms yet to be elucidated. Several key problems that remain to be understood are: (1) what are the co-factors and co-activators that interact with PPARgamma and allow it to regulate several crucial aspects of adipogenesis and insulin action; (2) What are the targets and signal transduction pathways used by leptin that have central and peripheral effects; (3) What are the new opportunities that are available for the development of novel treatments in obesity and related disorders. The areas of diabetes and obesity and diabetes have been of interest to researchers for some years. However, it is only recently that the tools of molecule biology, positional cloning and high throughput screening have been brought to bear on these problems. The PPARs and leptin are two examples of really important breakthroughs in the area of adipogenesis and energy balance, and there will likely be many more to come. We expect this Conference to stimulate the field by bringing leading academicians together with leading industrial scientists in a focused setting. Furthermore, by holding the Conference jointly with the Insulin Action/Diabetes Meeting, we expect to promote cross-fertilization in these areas which are closely linked scientifically. In the U.S. and Europe, 70-90% of all Type II Diabetes are obese, clearly indicating the need to tackle these problems in a unified scientific front.